But really, the bars are everywhere. Drugstores, gas stations, Bed Bath & Beyond, Staples and other various stores display energy and protein bars next to the typical buffet of gum and candies in checkout lines.

We live in a veritable protein-bar boom. There are over 1,000 nutrition bars on the market today, the Wall Street Journal reported in 2015. Yet a decade go, there were just 226 kinds.

The way we see it, there are two kinds of protein bars: The ones that look like a protein bar but act like a candy bar (looking at you, PowerBars, with 26 grams of sugar) and the ones that are actually a good source of fuel.

Within the latter category, not all protein bars are created equal.

Quality protein bars can have any (or all) of these attributes: clean ingredients (more on this below), high protein and low sugar.

Some bars are minimal when it comes to ingredients but have a good deal of sugar, while others pack a protein punch by adding not-so-clean ingredients for flavor.

In search of one protein bar to rule them all, we decided to map out a Venn diagram with the aforementioned three attributes.

The rules: We chose 10 bars that are widely available online or in stores. Whenever possible, we opted for chocolate or chocolate and peanut butter flavors because, well, chocolate rocks.

Here are our three criteria, defined:

Clean ingredients: Clean means different things to different people.We think we shouldn't need to gasp for air trying to read through a laundry list of ingredients that have infinite syllables. Bars that made the "clean" cut had minimal ingredients, and bars that had over 10 ingredients were deemed unclean, even if said bars were certified organic. (For the sake of this article, we deemed whey protein isolate and soy protein isolate "clean," though arguments can be made that only plant-based proteins are clean.)

The winner

Vegan, gluten-free, non-GMO, low glycemic — this bar seemingly does it all. It's got the texture of a Rice Krispies treat but none of the sweetness — tastes like a legit health food, for better or for worse.

The runners-up

Why it's prize-worthy: More than 15 grams of protein, fewer than 10 grams of sugar

What's inside: 190 calories, 21 grams of protein, 1 gram of sugar

Shout out to all the fiber in QuestBars: A whopping 14 grams of fiber represents 56% of the daily recommended intake. The cookies-and-cream flavor has real chunks of cookies that aren't as good as Oreos, but still satisfy cookie cravings. (Some QuestBar fans rave about microwaving them or baking them in the oven.)

Marco Borges, a nutritionist and trainer who's worked with Beyoncé, launched the 22 Days brand, and this bar definitely tastes #Flawless. It's like a peanut butter lover's dream, and has plenty of fiber and iron, too. Its first ingredient is brown rice protein concentrate. These bars are organic, non-GMO, gluten-free and soy free. The one downside: the 16 grams of sugar per bar.

Even though this bar has just four ingredients, it still manages to pack 17 grams of protein from whey protein. Legit. It gets its sweetness from honey and carob powder. WTF is carob powder? It's from carob, which is similar to cocoa. (Carob has less fat than cocoa and it's used to make healthier chocolate chips.)

Regular KIND bars hover around 6 grams of protein, but the Strong & KIND line has roughly 10 grams per bar. The nutty texture is on point and the bold flavors leave a spicy kick in your mouth. Note: We classified this bar as clean even though it has over 10 ingredients, since many of the ingredients are spices.

Hop to it — crickets are a great source of iron and they're a complete source of protein. Though they aren't vegan, crickets produce 100 times fewer greenhouse gases than cows, so they're an incredibly earth-friendly protein source. These bars taste like a chocolate bar collided with a hippie grocery store, and the high amount of fat (20 grams, roughly 31% of daily recommended intake) makes them very satisfying.

Taste buds say yes, ingredients list makes us walk back our love for this Clif Bar. Two of the first four ingredients are rice syrup and cane syrup, aka sugar. With 20 grams of protein, you're getting as much as you'd get from eating a small Greek yogurt topped with an ounce and a half of almonds.

Peanut butter lovers, rejoice. Eighteen grams of protein will satiate, as will the 13 grams of fat. With 12 grams of sugar, this bar narrowly missed the 10 grams of sugar cutoff for the "low sugar" classification in our Venn diagram.